Transmission performance of OSSB-RoF system using MZM electro-optical external modulator

Abstract

Both the EAM and the MZM, the commonly used electro-optical external modulators in RoF systems, have pointed on their transfer function curve at which link performance is optimized. In discussing the difficulty of maintaining the optimum modulator bias point, we prefer MZM because unlike EAM, it has a predictable transfer function shape. In this paper, the simulative investigation is analyzed and discussed to study the impact of extinction ratio with low chirp of single- and dual-electrode Mach–Zehnder (SEMZM and DEMZM) external modulators over RF power degradation introduced in Radio-over-Fiber (RoF) systems due to fiber dispersion, which is one of the limiting factors to RoF link. Our simulative results show that longer transmission distance spanned between a receiver and transmitter with minimum RF power degradation can be achieved by using low extinction ratio and chirp of MZM modulators. Further, it is also observed that a dual-electrode MZM with low extinction ratio and chirp enables the transmission of RF signal not only with minimal dispersion but also with maximal second-order harmonic (HD2) reduction.